Interfacial Chemistry Effects in the Electrochemical Performance of Silicon Electrodes under Lithium-Ion Battery Conditions.

Understanding the solid electrolyte interphase (SEI) formation and (de)lithiation phenomena at silicon (Si) electrodes is key to improving the performance and lifetime of Si-based lithium-ion batteries. However, these processes remain somewhat elusive, and, in particular, the role of Si surface termination merits further consideration. Here, scanning electrochemical cell microscopy (SECCM) is used in a glovebox, followed by secondary ion mass spectrometry (SIMS) at identical locations to study the local electrochemical behavior and associated SEI formation, comparing Si (100) with a native oxide layer (SiOx /Si) and etched with hydrofluoric acid (HF-Si). HF-Si shows greater spatial electrochemical heterogeneity and inferior lithiation reversibility than SiOx /Si. This is attributed to a weakly passivating SEI and irreversible lithium trapping at the Si surface. Combinatorial screening of charge/discharge cycling by SECCM with co-located SIMS reveals SEI chemistry as a function of depth. While the SEI thickness is relatively independent of the cycle number, the chemistry - particularly in the intermediate layers - depends on the number of cycles, revealing the SEI to be dynamic during cycling. This work serves as a foundation for the use of correlative SECCM/SIMS as a powerful approach to gain fundamental insights on complex battery processes at the nano- and microscales.

Survival of sharp force trauma in burnt bones: effects of environmental factors.

This study investigates how environmental variables, such as temperature and rainfall, affect previously induced cut marks on burnt bones. This research used non-serrated and serrated blade knives to inflict trauma on Sus scrofa ribs (n = 240). The bones were later burnt and left for 1 month in a taphonomic experimental facility. Qualitative and quantitative examinations were conducted using macroscopic and microscopic techniques to assess specific characteristics of the cut marks. Any changes to the dimension and morphology of the cut marks as well as their level of fragmentation were recorded.This study has led to three important outcomes: (1) identification of pre-existing cut marks is possible in reconstructed burnt bone fragments; (2) cut marks from different types of knife blades showed dissimilar responses to heat and the environment; and (3) specific environmental variables affect burnt bone fragmentation. These results have implications for trauma analysis on burnt remains in forensic anthropology casework.

Knife cut marks inflicted by different blade types and the changes induced by heat: a dimensional and morphological study.

Detailed information on skeletal trauma analysis of burned bone is important to ascertain the manner and cause of death in forensic casework. This research used three different knife types, one with a non-serrated blade, one a fine-serrated blade, and one a coarse-serrated blade, to inflict trauma to manually macerated Sus scrofa ribs (n = 240), and these ribs were later exposed to heat. Qualitative and quantitative analyses were conducted using macroscopic and microscopic techniques to assess specific characteristics of the cut marks. Differences in cut mark dimension and morphology of the ribs were investigated. After heat exposure, the cut marks on the rib samples remained recognisable and did not alter considerably. A level of dimensional and morphological preservation was reliant on the cutting action and the features of the knife blade as well as surrounding bone injury. The cut marks inflicted by the non-serrated blade remained recognisable despite exposure to the burning process. However, the cut marks inflicted by the coarse-serrated blade were likely to change significantly when exposed to heat. This study leads to two important results: (1) identification of pre-existing cut marks prior to heat exposure is possible in reconstructed burned bone fragments, and (2) cut marks from different types of knife blades showed dissimilar responses to heat. The outcomes obtained in this study stressed the need to adopt great care with the effects of heat on skeletal trauma analysis.

Measuring dimensional and morphological heat alterations of dismemberment-related toolmarks with an optical roughness metre.

This experimental study provides a further understanding of the post-burning nature of sharp force trauma. The main objective is to analyse the distortion that fire may inflict on the length, width, roughness, and floor shape morphology of toolmarks induced by four different implements. To this end, four fresh juvenile pig long bones were cut with a bread knife, a serrated knife, a butcher machete, and a saw. A total of 120 toolmarks were induced and the bone samples were thus burnt in a chamber furnace. The lesions were analysed with a 3D optical surface roughness metre before and after the burning process. Afterwards, descriptive statistics and correlation tests (Student's t-test and analysis of variance) were performed. The results show that fire exposure can distort the signatures of sharp force trauma, but they remain recognisable and identifiable. The length decreased in size and the roughness increased in a consistent manner. The width did not vary for the saw, serrated knife, or machete toolmarks, while the bread knife lesions slightly shrunk. The floor shape morphology varied after burning, and this change became more noticeable for the three knives. It was also observed that the metrics of the serrated knife and machete cut marks showed no significant variations. Our results demonstrate that there is a variation in the toolmark characteristics after burning. This distortion is dependent on multiple factors that influence their dimensional and morphological changes, and the preservation of class features is directly reliant upon the weapon employed, the trauma caused, and the burning process conditions.

Dental age estimation based on pulp chamber/crown volume ratio measured on CBCT images in a Spanish population.

Dental age estimation in living individuals is one of the most frequent requests undertaken by forensic odontologists. The aim of this study was to estimate the dental age by pulp/tooth volume ratio, as measured on cone beam computed tomography (CBCT) images, in a Spanish population. This study included 313 teeth from 107 adult individuals, 56 females and 51 males with a mean age of 44 ± 14 years. The statistical analysis of the results took account of clustering (multiple teeth in individuals). Linear regression models were constructed on the relationship between pulp/tooth volume ratio and chronological age for each tooth type. The highest coefficient of determination (R2) value was provided by the upper incisors (36.6%), and the difference between chronological and estimated age was less than 5 years in 31.3% of the sample and less than 10 years for 65.7%. CBCT is an accurate imaging technique to measure dental volume with a relatively low radiation dose, and it can be used to assess dental age in living adult individuals. Volumetric changes in the pulp cavity with increasing age proved valuable to estimate dental age in this Spanish population.

Through fire and flames: post-burning survival and detection of dismemberment-related toolmarks in cremated cadavers.

During a homicide investigation in which fire has been used to reduce the size of the cadaver and conceal the evidence of injuries, the identification of perimortem trauma presents a challenge, in particular in cases when the perpetrator has dismembered the body followed by burning the remains. It is therefore important to understand the effects which heat causes on fresh bone. The aim of this paper is to perform a pilot study on the survival ratio of toolmarks in different anatomical regions associated with dismemberment, and a descriptive analysis of the variables that may potentially influence the post-burning survival and detection. To achieve this, three donated embalmed cadavers were used to simulate a case in which an attempted dismemberment and burning had occurred. Fifty-five pre-burning injuries were manually induced: 30 using a machete to inflict chopping trauma, and 25 with a serrated bread knife to inflict sharp force trauma, on the thigh, knee, ankle and wrist. The cadavers were cremated in a furnace at Madrid's Cementerio Sur and the burnt remains were analysed at the Laboratorio de Antropología y Odontología Forense of the Universidad Complutense de Madrid. Not all pre-burning injuries inflicted were visible after the cremation process; only 13% were detected in this experiment. Toolmarks can be masked, modified, destroyed or overlooked from the outset of the procedure due to several factors which influence the post-burning survival and detection of toolmarks and contribute to conceal the evidence of trauma. Additional research should be done to study further variables which affect the post-burning visibility of sharp force trauma.

Establishing a minimum PMI for bone sun bleaching in a UK environment with a controlled desert-simulated comparison.

Microenvironments play a significant part in understanding the post-mortem interval in forensic taphonomy. Recently, the value of weathering factors in relation to obtaining a PMI has been investigated further. In this study, observations were made to calculate the length of time it takes for three different bone elements (femur, rib, and scapula) to bleach in a UK summer and winter. This research also investigated whether there were any physicochemical modifications to the bone caused by bleaching. Porcine femora, scapulae, and ribs were placed into open and shaded areas of an outdoor research facility located in Oxfordshire, UK, during summer (July-Sep) and winter months (Dec-Mar). The specimens were monitored at 3-week intervals using photography, and an observational scoring method was developed to quantify the extent of bleaching. As temperatures are typically much lower in the UK compared with warmer climates, a controlled indoor-simulated desert experiment was also undertaken to be used as a control. This allowed sun bleaching and changes to the bone chemistry to be monitored in a controlled, high-UV environment for comparison with the UK outdoor experiments. Fourier transform infrared spectroscopy (FTIR) was employed to analyze physicochemical modifications to both the mineral and organic components of the bone. The FTIR was used to calculate crystallinity index (CI), mineral to organic ratio, and the relative amount of carbonate concentrations. Weather data was collected and a positive correlation was found between both ultraviolet (UV) levels and accumulated degree days (ADD) when compared with observational bleaching scores. Bleaching (whitening) of the bone samples occurred in both seasons but at different rates, with the bleaching process occurring at a slower rate in winter. During summer, the initial bleaching process was evident at 6 weeks, and by 9 weeks, the bones were an off-white colour. During the winter period, whitening of the bone started at 9 weeks; however, only the scapula and rib samples displayed a similar off-white colour. This colouration was observed at 13 weeks rather than at 9 weeks. The desert simulation samples started bleaching in a similar pattern to the outdoor samples after 1 week but the bones did not fully bleach. The bone chemistry, based on physicochemical properties obtained from the FTIR, showed a significant statistical difference between the simulated desert and winter season when compared against a control sample. For the winter samples, the mineral to organic ratio was significantly higher than that in the control, suggesting a reduction in the proportion of organic. For the samples in the simulated desert environment, the crystallinity index was significantly higher than that in the control samples, suggesting an increase in crystallinity. The results of this experiment support the fact that it is possible to achieve bleaching in a UK environment and that the minimal time frame for this to occur differs in seasons.

Baggage scanners and their use as an imaging resource in mass fatality incidents.

Disaster victim identification following a mass fatality incident is focussed on identifying the deceased and returning them to their families as quickly as possible, while gathering as much information as practical to aid investigators in establishing the cause of the incident. Ante-mortem data is gathered and compared with the post-mortem data obtained in order to positively identify the deceased. This paper presents results from a study concerned with the first part of the process of identifying the deceased-the triage or Primary Survey and how this can be done without access to hospital facilities such as conventional X-ray imaging or computed tomography. In particular, this study focuses on the imaging undertaken prior to the opening of the body bag by a multidisciplinary team, and how this imaging can assist particularly when forensic anthropologists are involved in the identification process. There are several advantages to imaging the body bags before they are opened and one of the most important is safety. Thus, this paper examines the viability of using a baggage scanner as a practical resource for X-ray imaging, as many regions worldwide may not be able to access conventional imaging equipment. Baggage scanners are readily available and found in airports and various government buildings. The baggage scanner is particularly suited to this task and produces images that can be used by forensic anthropologists to distinguish between human and non-human remains, identify items of evidence and personal effects, and even perform a preliminary or partial biological profile. When considering their response plans, emergency responders should consider including baggage scanners as a contingency for screening body bags if no other imaging system is available.

The effect of diet and sociopolitical change on physiological stress and behavior in late Roman-Early Byzantine (300-700 AD) and Islamic (902-1,235 AD) populations from Ibiza, Spain.

OBJECTIVES: This study evaluated chronological changes in physiological stress and levels of habitual loading of Ibizan populations from the Late Roman-Early Byzantine (LREB) to the Islamic period (300-1,235 AD) using measures of body size and bone cross-sectional properties to compare Urban LREB, Urban Medieval Islamic, and Rural Medieval Islamic groups. It also explored the effect of diet, modeled using stable isotopes, on physiological stress levels and behavior. MATERIALS AND METHODS: The sample comprised individuals from three archeological populations: Urban Late Roman- Early Byzantine (LREB) (300-700 AD), Medieval Urban Islamic (902-1,235 AD), and Medieval Rural Islamic. Bone lengths, femoral head dimensions, and cross-sectional properties, diaphyseal products and circumferences, were compared to assess differences in body size and habitual loading in 222 adult individuals. Ordinary least squares regression evaluated the correlations between these measures and carbon (δ13 C) and nitrogen (δ15 N) stable isotope ratios in 115 individuals for whom both isotope values and osteological measures are available. RESULTS: The Medieval Rural Islamic group had shorter stature and reduced lower limb cross-sectional properties compared to the two urban groups. Limb shape differs between Urban LREB and Urban Medieval Islamic groups. Measures of body size length were positively correlated with δ13 C values in all individuals and separately in the Urban LREB and Rural Medieval Islamic groups. δ15 N showed a positive correlation with left humerus shape in the Urban LREB sample. CONCLUSIONS: The low stature and cross-sectional properties of the Medieval Rural Islamic group may be an indicator of greater physiological stress, potentially due to poorer diet. Positive correlations between measures of body size and δ13 C values further suggest that greater access to C4 resources improved diet quality. Alternatively, this relationship could indicate greater body size among migrants from areas where individuals consumed more C4 resources.

Histomorphometric analysis of osteocyte lacunae in human and pig: exploring its potential for species discrimination.

In recent years, several studies have focused on species discrimination of bone fragments by histological analysis. According to literature, the most consistent distinguishing features are Haversian canal and Haversian system areas. Nonetheless, there is a consistent overlap between human and non-human secondary osteon dimensions. One of the features that have never been analyzed for the purpose of species discrimination is the osteocyte lacuna, a small oblong cavity in which the osteocyte is locked in. The aim of this study is to verify whether there are significant quantitative differences between human and pig lacunae within secondary osteons with similar areas. Study sample comprises the midshaft of long bones (humerus, radius, ulna, femur, tibia, and fibula) of a medieval human adult and a juvenile pig. Sixty-eight secondary osteons with similar areas have been selected for each species and a total of 1224 osteocyte lacunae have been measured. For each osteon, the total number of lacunae was counted, and the following measurements were taken: minimum and maximum diameter, area, perimeter, and circularity of nine lacunae divided between inner, intermediate, and outer lacunae. Statistical analysis showed minimal differences between human and pig in the number of lacunae per osteons and in the minimum diameter (P > 0.05). On the contrary, a significant difference (P < 0.001) has been observed in the maximum diameter, perimeter, area, and circularity. Although there is the need for further research on different species and larger sample, these results highlighted the potential for the use of osteocyte lacunae as an additional parameter for species discrimination. Concerning the difference between the dimensions of osteocyte lacunae based on their position within the osteon (inner, intermediate, and outer lacunae), results showed that their size decreases from the cement line towards the Haversian canal both in human and pig.

Histomorphological analysis of the variability of the human skeleton: forensic implications.

One of the fundamental questions in forensic medicine and anthropology is whether or not a bone or bone fragment is human. Surprisingly at times for the extreme degradation of the bone (charred, old), DNA cannot be successfully performed and one must turn to other methods. Histological analysis at times can be proposed. However, the variability of a single human skeleton has never been tested. Forty-nine thin sections of long, flat, irregular and short bones were obtained from a well-preserved medieval adult human skeleton. A qualitative histomorphological analysis was performed in order to assess the presence of primary and secondary bone and the presence, absence and orientation of vascular canals. No histological sections exhibited woven or fibro-lamellar bone. Long bones showed a higher variability with an alternation within the same section of areas characterized by tightly packed secondary osteons and areas with scattered secondary osteons immersed in a lamellar matrix. Flat and irregular bones appeared to be characterized by a greater uniformity with scattered osteons in abundant interstitial lamellae. Some cases of "osteon banding" and "drifting osteons" were observed. Although Haversian bone represent the most frequent pattern, a histomorphological variability between different bones of the same individual, in different portions of the same bone, and in different parts of the same section has been observed. Therefore, the present study has highlighted the importance of extending research to whole skeletons without focusing only on single bones, in order to have a better understanding of the histological variability of both human and non-human bone.

Greater Impacts of Incubation Temperature and Moisture on Carbon and Nitrogen Cycling in Poultry Relative to Horse Manure-based Soil Amendments.

Manure-based soil amendments (MBSAs) must be managed optimally to maximize N concentration and availability while minimizing environmental impacts (e.g., greenhouse gas [GHG]) emissions. We conducted an 83-d incubation study to determine the effects of different moisture (60 or 120% of water-holding capacity [WHC]) and temperature (4 or 20°C) conditions during the decomposition of MBSAs. We measured CO, CH, and NO emissions and total C, total N, NH, and NO during the decomposition of chicken MBSA and two understudied MBSAs (turkey and horse). Total N decreased by 38 to 50% after 83 d in poultry MBSAs incubated at 20°C and 120% WHC, whereas NH concentration peaked at 30 d. In contrast, poultry MBSAs incubated at 60% WHC or 4°C had limited N losses but higher CO and/or NO emissions. Horse MBSA incubated for 83 d at 20°C and 60% WHC had two- to threefold higher C losses, 53 to 68% higher total N, and two to three orders of magnitude higher NO concentrations than at wetter and/or colder incubation conditions. Horse MBSA incubated at 20°C and 60% WHC had 13- to 130-fold (CH) and 4- to 70-fold (NO) higher emissions than horse MBSA incubated at 4°C. In contrast, CH emissions peaked at 120% WHC and 20°C. Overall, incubating horse MBSA at 20°C and 60% WHC minimized tradeoffs between maximizing N concentration and availability and minimizing GHG emissions during decomposition, whereas we found no ideal decomposition conditions for poultry MBSAs.

Differentiating human versus non-human bone by exploring the nutrient foramen: implications for forensic anthropology.

One of the roles of a forensic anthropologist is to assist medico-legal investigations in the identification of human skeletal remains. In some instances, only small fragments of bone may be present. In this study, a non-destructive novel technique is presented to distinguish between human and non-human long bones. This technique is based on the macroscopic and computed tomography (CT) analysis of nutrient foramina. The nutrient foramen of long bone diaphyses transmits the nutrient artery which provides much of the oxygen and nutrients to the bone. The nutrient foramen and its canal were analysed in six femora and humeri of human, sheep (Ovies aries) and pig (Sus scrofa) species. The location, position and direction of the nutrient foramina were measured macroscopically. The length of the canal, angle of the canal, circumference and area of the entrance of the foramen were measured from CT images. Macroscopic analysis revealed the femora nutrient foramina are more proximal, whereas humeri foramina are more distal. The human bones and sheep humerus conform to the perceived directionality, but the pig bones and sheep femur do not. Amongst the parameters measured in the CT analysis, the angle of the canal had a discriminatory power. This study shows the potential of this technique to be used independently or complementary to other methods in distinguishing between human and non-human bone in forensic anthropology.

Application of biochar and nitrogen influences fluxes of CO2, CH4 and N2O in a forest soil.

Nitrogen (N) fertilization of forests for increasing carbon sequestration and wood volume is expected to influence soil greenhouse gas (GHG) emissions, especially to increase N2O emissions. As biochar application is known to affect soil GHG emissions, we investigated the effect of biochar application, with and without N fertilization, to a forest soil on GHG emissions in a controlled laboratory study. We found that biochar application at high (10%) application rates increased CO2 and N2O emissions when applied without urea-N fertilizer. At both low (1%) and high biochar (10%) application rates CH4 consumption was reduced when applied without urea-N fertilizer. Biochar application with urea-N fertilization did not increase CO2 emissions compared to biochar amended soil without fertilizer. In terms of CO2-eq, the net change in GHG emissions was mainly controlled by CO2 emissions, regardless of treatment, with CH4 and N2O together accounting for less than 1.5% of the total emissions.

Histological determination of the human origin from dry bone: a cautionary note for subadults.

Anthropologists are frequently required to confirm or exclude the human origin of skeletal remains; DNA and protein radioimmunoassays are useful in confirming the human origin of bone fragments but are not always successful. Histology may be the solution, but the young subadult structure could create misinterpretation. Histological tests were conducted on femur and skull of 31 human subjects. Each sample was observed focusing on presence or absence of fibrous bone, lamellar bone, radial lamellar bone, plexiform bone, reticular pattern, osteon banding, Haversian bone, primary osteons, secondary osteon and osteon fragments. Samples were divided into five age classes; 1 (<1 year), 2 (1-5 years), 3 (6-10 years), 4 (11-15 years) and 5 (16-20 years). Regarding femurs, class 1 presented the following: 87.5% fibrous bone, 37.5% plexiform bone, 12.5% reticular pattern and 12.5% lamellar bone radially oriented. Class 2 showed 37.5% of fibrous bone, 12.5% of reticular pattern and 37.5% of osteon banding. In the higher age classes, the classical human structures, lamellar bone and osteons were frequently visible, except for one case of reticular pattern, generally considered a distinctive non-human structure. The situation appeared different for the skull, where there was a lack of similar information, both in human and non-human. An analysis of the percentage of lamellar bone and osteons was conducted on femur and skull fragments. A trend of increase of primary osteon number and a decrease of the lamellar bone area has been detected in the femur. The present study has therefore shed some light on further pitfalls in species determination of subadult bone.

Preserved brains from the Spanish Civil War mass grave (1936) at La Pedraja1, Burgos, Spain.

During the excavation of the Spanish Civil War mass grave at La Pedraja (Burgos, Spain), 104 individuals were found interred within it, 45 of which displayed brains that were preserved but dehydrated and reduced in size. This exceptional finding has resulted in the formation of a multidisciplinary team, with the aim of obtaining as much information as possible and to primarily understand the taphonomic phenomena that has led to the preservation of these brains. The following types of analyses were undertaken on three of these brains: macroscopy, histology, radiology, chemical-toxicology, genetics, chemical analysis of the soil and 3D modelling for stereolithography. The historical context was considered, plus all archaeological and other forensic data provided by the investigation of the mass grave. The results of the analyses on these morphologically identifiable human brains confirmed the presence of nerve structures, fatty acids, and in one case ante-mortem evidence for an intracranial haemorrhage. The fatty acid profile corresponds to the process of saponification. Therefore, the interpretation is that the preservation of these brains at the mass grave of La Pedraja was due to the saponification process, which was influenced by the manner and cause of death, the chemical composition of the brain, the physicochemical properties of the soil and the meteorological conditions at the time.

What do bones tell us? The study of human skeletons from the perspective of forensic anthropology.

Human remains are present in a number of contexts. Some of these are archaeological burial sites, which can comprise individual or mass graves burials. Human remains are usually found buried (or cremated), but they can also be found in museums and in universities, as part of their anatomical collections. Human remains can be found in churches as relics, in ossuaries, and as part of objects. Hence human remains refer to not just a complete skeleton, but also apart of a bone or tooth, hair and mummified remains. In more recent forensic, police or medico-legal cases, human skeletal remains can be found in a number of contexts, such as fire scenes, natural disasters, clandestine graves, or on the surface in open areas (e.g. a woodland). One aspect ofphysical anthropology is that which studies human skeletal remains in order to reconstruct the past, understand human variation, and provide information about the deceased individuals, such as their age at death, sex, ancestry, stature, pathological conditions or traumatic injuries; the remains from medico-legal or police cases fall under the branch offorensic anthropology.

An overview of age estimation in forensic anthropology: perspectives and practical considerations.

CONTEXT: Information on methods of age estimation in physical anthropology, in particular with regard to age-at-death from human skeletal remains, is widely available in the literature. However, the practicalities and real challenges faced in forensic casework are not always highlighted. OBJECTIVES: To provide a practitioner's perspective, regarding age estimation in forensic anthropology (both in the living as well as the dead), with an emphasis on the types of cases, the value of such work and its challenges and limitations. METHODS: The paper reviews the current literature on age estimation with a focus on forensic anthropology, but it also brings the author's personal perspective derived from a number of forensic cases. RESULTS AND CONCLUSIONS: Although much is known about what methods to use, but not always how to apply them, little attention has been given in the literature to the real practicalities faced by forensic anthropologists, for example: the challenges in different types of scenarios; how to report age estimations; responsibilities; and ethical concerns. This paper gathers some of these aspects into one overview which includes the value of such work and the practical challenges, not necessarily with the methods themselves, but also with regard to how these are applied in the different cases where age estimation is required.

Examining thermally induced movement of the fatal fire victim.

Investigating a fatal fire scene comprises analysis not only of the fire's development to identify the point of fire origin and ignition source, but analysis of a victim's position and their relationship within the scene. This work presents both qualitative and quantitative results from experimentation investigating the effect of a real fire environment on the human body, and how the position of a victim at the post burn investigation stage may be significantly different to the position at fire ignition. Qualitative observations were undertaken on the burning of 39 compartment and vehicle scenes from ignition through to suppression, each containing a human cadaver. The results of analysis question the validity of previous work based on cremation observations. Quantitative results were produced by recording 13 points on the body on the X, Y and Z axis, both pre and post burn on a smaller dataset of ten compartment burns. Results have enabled a more robust assessment of thermally induced movement of the body within the scene along each axis, evidencing that pugilism is not the universal reaction of the fatal victim to thermal exposure, with extension of the upper limbs far more common than has been previously reported.

Solving the inverse problem of post-mortem interval estimation using Bayesian Belief Networks.

Bayesian Belief Networks (BBNs) can be applied to solve inverse problems such as the post-mortem interval (PMI) by a simple and logical graphical representation of conditional dependencies between multiple taphonomic variables and the observable decomposition effect. This study is the first cross-comparison retrospective study of human decomposition across three different geographical regions. To assess the effect of the most influential taphonomic variables on the decomposition rate (as measured by the Total Decomposition Score (TDS)), decomposition data was examined from the Forensic Anthropology Research Facility at the University of Tennessee (n = 312), the Allegheny County Office of the Medical Examiner in Pittsburgh, US (n = 250), and the Crime Scene Investigation department at Southwest Forensics in the UK (n = 81). Two different BBNs for PMI estimations were created from the US and the UK training data. Sensitivity analysis was performed to identify the most influential parameters of TDS variance, with weaker variables (e.g., age, sex, clothing) being excluded during model refinement. The accuracy of the BBNs was then compared by additional validation cases: US (n = 28) and UK (n = 10). Both models conferred predictive power of the PMI and accounted for the unique combination of taphonomic variables affecting decomposition. Both models had a mean posterior probability of 86% (US) and 81% (UK) in favor of the experimental hypothesis (that the PMI was on, or less than, the prior last known alive date). Neither the US nor the UK datasets represented any cases below 'moderate' support for the value of PMI evidence. By applying coherent probabilistic reasoning to PMI estimations, one logical solution is provided to model the complexities of human decomposition that can quantify the combined effect of several uncertainties surrounding the PMI estimation. This approach communicates the PMI with an associated degree of confidence and provides predictive power on unknown PMI cases.